Rotary piston internal combustion engine



Sept. s, 1970 H. ZU HOHENLOHE ROTARY PIS'ION INTERNAL COMBUS'IION ENGINE Filed Nov. 25, was

INVENTOR HUBERT zu HOHENLOHE BY C 7 momev United States Patent O 3528084 ROTARY PISTON INTERNAL COMBUSTION ENGINE Hubert zu Hohenlohe, Esehenau, Waldhof, Germany, assignor to Daimler-Benz Aktiengesellschaft, Stuttgart- Unterturkheim, Germany Filed Nov. 25, 1968, Sex. N0. 778,708

Claims priority, application Germany, Dec. 2, 1967,

1,576902 Int. C1. F02b 53/06 U.S. Cl. 123-8.07 9 Claims ABSTRACT OF THE DISCLOSURE A rotary piston internal combustion engine of threedisk construction in which three disks are rotatably supported on the eccentn'cs of an eccentric sha.ft mutually displaeed by 120; each of the pistons valves the discharge apertures of inlet and outlet channels while each of the three inlet channels downstream of the throttle valve or each of the three suction spaces between inlet and outlet channels of each disk is connected by way of a line adapted to be closed With the compression chamber of that disk whose eccentric leads the eccentric of the firstrnentioned disk by 120; the orifices of the lines in the compression ehambers are located within the area of the major axis.

The present invention relates to a rotary piston internal cornbustion engine of trochoidal three-disk comstruction in which three pistons, that control or valve apertures of inlet and outlet channels, are supported on eccentrics of an eccentric shaft arranged mutually displaced by 120.

It has been found that rotary piston internal combustion engines run very unevenly during idling and smaller partial loads. This uneven or unsteady operation is Conditioned by the fact that in the overlap dead-center point exhaust gases reach into the suction space which collect in particular in the forward or leading part of the working chamber and therewith render more diflicult the ignition. The exhaust gas volurne flowing over into the suction space is particularly of significance if by reason of a closed throttle valve, a considerable vacuum prevails in the suction space, i.e., during idling and smaller partial loads.

It has already been proposed heretofore to supply fresh gases under pressure to the space between inlet and ontlet channel whereby an overflow of exhaust gases is to be prevented. This fresh gas is rernoved from the compression chamber of the same disk. The disadvantage of this arrangement resides in that at the beginning of the overlap, i.e., when the corresponding piston corner valves or has just valved the orifice aperture of the suction channel, no excess pressure prevails as yet in the compression chamber so that at the indicated moment, the overflow of exhaust gases cannot be prevented. Another proposal made heretofore suggests with a multidisk engine to provide within the housing in proximity to the major axis (cold are), orifices in the working chambers and to connect the sarne With each other. It is ossible therewith to push fuel-air mixture out of the compression chamber into the leading art of the subsequent or trailing suction chamber, to displace thereat the exhaust gases and therewith to improve the ignition capability of the fuel-air mixture. An overflow of exhaust gases into the compression ehamber, however, cannot be prevented With the aid of this arrangement.

The present invention aims at considerably reducing 3528084 Patented Sept. 8, 1970 with a three-disk engine, the exhaust gas volume reaching the suction chambers and therewith to improve the operating quietness of the engine during idling and smaller partial loads. For this purpose, the cornpression chamber of each disk is connected according to the present invention by way of an overflow line with the suetion space of that disk whose eccentric trails the eceentric of the first-mentioned disk by 120. The orifice of the overflow line in the compression chamber lies thereby Within the area of the major axis (cold are), most appropriately about 15 behind the major axis as viewed in the direction of rotation of the piston. On the other side, the overflow line terminates either in the inlet channel downstream of the throttle valve or directly in the trochoid-hollow space between the apertures of the inlet and outlet channel. This arrangernent eilects that during the period of overlap, fresh gases which are under excess pressure, reach into the suction space, that a higher pressure compared to the outlet ehannel builds up in the suction space and therewith the overflow of exhaust gases into the suction chamber is prevented. This higher pressure in the suction space is achieved already at the beginning of the period of overlap, i.e. directly after the piston corner leading the suction charmber has swept past the aperture of the inlet channel or of the overflow line because at this moment a corresponding high pressure prevails in the compression chamber of the disk connected by way of the overflow line. It is thus assured that at least in the leading and central portions of the working charnbers, no exhaust gases are stored so that at the moment of the ignition, an ignitable mixture is always located in front of the ignition source.

A partieularly simple construction of the arrangement according to the present invention can be achieved in that the overflow lines are arranged in theil' entire length Within the housing of the engine, for example, as bores in the casing and intermediate parts.

Since an overflow of fuel-air mixture from disk to disk is to take place only during the operation of the engine at idling or smaller partial loads, it is necessary to provide Closure mechanisms which close the overflow lines With larger partial loads and full load. These elosure mechanisms are appropriately connected With the throttle valves and are actuated simultaneously With the same.

Accordingly, it is an object of the present invention to provide a multi-disk rotary piston internal combustion engine which avoids by simple means the aforementioned shortcomings and drawbacks encountered in the prior art.

Another object of the present invention resides in a rotary piston internal combustion engine which operates smoothly also at idling speed and smaller partial loads.

A further object of the present invention resides in a rotary piston internal combustion engine in which an overflow of exhaust gases into the working chambers during the suction phase is far-reachingly prevented.

Still a further object of the present invention resides in a rotary piston internal combustion engine of the type described above in which an ignitable mixture is always assured for ignition by the ignition source.

Still another object of the present invention resides in a rotary piston internal combustion engine of the type described above which achieves all of the aforementioned aims and objects, yet is simple in construction and can be readilyassernbled and manufactured without difliculties.

These and further objects, features and advantages of the present invention Will become more obvions from the following description when taken in connection With the accompanying drawing which shows, for purposes of illustration only, one embodiment in accordance With the present invention, and wherein:

The single figure is a schematic view of an internal cornbustion engine according to the present invention in which the individual disks, that are in practice disposed one behind the other in the axial direction of the engine, are illustrated adjacent ne another for the sake of clarity.

Referring now to the single figure 0f the drawing, reference numerals 1a, 1b and 1c designate conventional engine casings within which rotate the pistons 3a, 3b and 3c in the direction of arrows 2a, 2b and 2c, respectively. The Center points 4a, 4b and 4c of the pistons 3a, 3b and 3c rotate a1ong the arcs Sa, b and 5c, respectively. The points 4a, 4b and 4c simultaneously represent the eccentric center points of an eccentric shaft in the illustrated position of the pistons 3a, 3b and 3c While the circles Sa, 5b and 5c represent the paths of rotation thereof. The eccentrics are mutually displaced by 120, in the illustrated example in such a manner that the ignition sequence is a, c, b. The only schematically indicated ignition sources 6a, 612 and 6c as we11 as the inlet channels 7a, 7b and 7c With the throttle valves 8a, 8b and 8c and the outlet channels 9a, 9b and 9c are arranged in the casings 1a, 1b and 1c. The engine so far described is known per se and forms no part of the present invention.

Two disks each are connected with each other by overflc' w lines 10a, 10b and 10c, and more particularly one line each 10a, 10b and 100 leads from the compression chamber 11a, 11b and-11a of a disk to the suction channel 7c, 7a and 7b of that disk whose eccentric trails the eccentric of the first-mentioned disk by 120 The discharge apertures of the overflow lines 10a, 10b and 100 in the compression chambers 11a, 11b and 11c are disposed about 15 behind the major axis a, 20b and 20c, as viewed in the direction of arrows 2a, 2b and 2c, respectively ie., within the area of the co1d arc 21a, 21b and 21c, respectively. In the illustrated position of the pistons, an overflow of fuel-air mixture takes place from the compression chamber 11b by way of the line 10b into the suction channel 7a whereby a penetration of exhaust gases into the suction space is prevented during the overlap. N0 excess pressure has formed as yet in the compression chamber 11a as well as in the chamben and correspondingly also in the inlet channel 7c and 7b connected therewith. This is not necessary since in the illustrated position of the pistons 3b and 3c, exhaust gases cannot mach into the compression chamber.

The overflow lines 10a, 10b and 100 are adapted to be closed off by closure mechanisms 12a, 12b and of any conventional, known construction in order to be able to prevent an overflow of fuel-air mixture during the operation of the engine at larger partial 1oads and full load. The closure mechanisrns 12a, 12b and 12c are appropriately actuated together With the throttle valves 8a, 8b and 8c from the drivers foot pedal.

While I have shown and described only one embodiment in accordance with the present invention, it is understood that the sarne is not limited thereto but is susceptible of numerous changes and modifications as known to a erson skilled in the art, and I therefore do not wish 10 be limited to the details shown and described herein but intend t0 cover all such changes as are within the scope of those skilled in the art.

I claim:

1. A rotary piston internal combustion engine of threedisk construction in which three piston means each valving the apertures of inlet and outlet channels, are rotatably supported on eccentrics of an eccentric shaft which are arranged mutually displaoed by 120, characterized by 1ine means adapted to be closed and operativey counecting the area of a respective suction space of each disk with the compression chamber of that disk whose eccentric leads by 120 the eccentric of the first-mentioned disk, the orifices of the line means being located .in a corresponding compression chamber within the area of the major axis thereof.

2. An interna1 combustion chamber according to clain1 1, wherein the orifice of the line means are located in the cornpression chambers within the area of the cold arc.

3. An internal combustion engine according to claim 1, wherein the line means connect a respective compression chamber With the corresponding inlet channel downstream of its throttle valve.

4. A rotary piston internal combustion engine according to claim 1, Wherein the 1ine means connect a respective compression chamber With the corresponding suction space between the inlet and outlet channels of the respective disk.

5. An internal combustion engine according to claim 1, wherein the orifice of the line means in the compression chambers are located about 15 behind the major axis as viewed in the direction of rotation of the piston.

6. An internal combustion engine according to claim 5, w herein the line means are arranged completely Within the housing of the internal combustion engine.

7. An internal combustion engine according to claim 6, wherein the line means connect a respective compression chamber with the corresponding inlet channel downstream of its throttle valve.

8. A rotary piston internal combustion engine according to claim 6, wherein the line means connect a respective compression chamber With the corresponding suction space between the inlet and outlet channels of the respective disk.

9. An internal combustion engine according to claim 5, Wherein the line means are arranged completely within the housing of the internal combustion engine.

References Cited UNITED STATES PATENTS 3077867 2/1962 Froede. 3168078 2/ 1965 Lamm. 3,446,190 5/1969 Bensinger et a1. 1238 ALLAN D. HERRMANN, Primary Examiner U.S. C1. X.R. 

